Booster pump



March 7, 1961 R. M. KENDIG 2,973,717

BOOSTER PUMP Filed Oct. 29, 1957 vgiiim 9801 INVENTOR. Hebert M Kndig'BY f aw 0. A ttoz'ney Robert M. Kendig, Tralford, Pa.,

" a limited volume of fluid 2,973,717 BOOSTER PUMP assignor toWestinghouse Air Brake Company, Wilmerding, Pa., a corporation ofPennsylvania Filed Oct. 29, 1957, Ser. No. 693,100 8 Claims. 01.103-152operating pressures are'maintained throughout the system; a normaloperating pressure supplied by a comi pressor, and a high operatingpressure supplied by a separate high pressure compressor. In themajority of such systems, space and Weight considerations in additionto' United ta ate t expense makes the additional high pressurecompressor 4 impractical.

' According to the invention, there is provided a selfcontained boosterpump adapted to he installed ina fluid pressuresystem supplied withfluidunder anormal operating pressure, said booster pump being operativeresponsively to the normalpressure .to supply limited quantities offluid at a pressure higher than the normal pressure. The booster pumpcomprises a minimumof parts including two symmetrically-arranged pairsof diaphragm type pistons of equal effective area operative by saidfluid under normal pressure to oscillate a rocker arm and toggle leverto control positioning of pressure inlet valves in such a' manner as toapply normal pressure alternately to first one pair of diaphragm pistonsand then the other to cause the opposite pair of diaphragm pistons toboost the normal pressure to the higher pres sure.

It is accordingly the principal i object of: this invention to provideaninexpensivej self-contained and compact boosterpump of small size andweight'operative responsively to' fluid under a normalpressure to supplyat a pressure higher than said normal pressure. I v The" above objectand, other'objectsfand advantageswill aphragm pistons 13 and 14 beingcontained in bore 11 and diaphragm pistons '15 and 16 being contained inbore 12. The diaphragm pistons 14 and 16 are clamped around theirrepective peripheries between the intake portion 2 and the centerportion v3 of the casing 1. The diaphragm pistons 13 and 15 are clampedaround their respective periphery between the check valve portion 4 andthe center portion 3 of the casing 1. Diaphragm pistons 13 and 14 arepositioned within the bore 11 in substantially parallel relation andjoined by a connecting rod 17 so as to move together. Diaphragm pistons15 and 16 are positioned within the bore 12 in substantially parallelrelation and joined by a connecting rod 18 so as to move together. Aplurality of piston chambers 19, 20, 21and 22 are defined by the bores11 and 12 and the diaphragm pistons, chambers 19 and 21 being defined bybore 11 and respective diaphragm pistons 14 and 13, chambers 20 and 22being defined by bore 12 and respective diaphragm pistons '16 and 15. V

The connecting rods 17 and 18 of the two pairs of diaphragm pistons arelinked together at their respective mid-points by a rockerarm24'pivota1ly mounted as by a pivot pin 23 on the center portion 3 of thepump body 1 within a rocker chamber 25 connecting the two bores 11 and12. The outer extremities of the rocker arm 24 .are provided with slots26 and 27 to receive pins 28 and 29 that extend through holes at themid-points of the respective connecting rods Hand 18. Separably at- -toa pin 34.fixed at the end of the toggle lever, said pin being movable inan arcuate slot 35 in the arm 30.

The other end of the spring 33 is connected to a pin 36 near the end ofthe arm 30. Toggle lever 31 is thus become apparent from the"followingdetailedfldescription Q of a booster pump embodying the invention whenread in connection with the accompanying drawing, in ,which thesingle'figure isa vertical sectionalview, on enlarged scale, of anillustrative embodiment of the booster pump.

Description As shown in the drawing, the booster-pump comprises asectionalized pump body or casing l'having several por,' 1'tionsarranged in the followingsequence: an intake portion 2, a centerportion'3, acheckgvalve portion d, and a' "compressionheadportion 5, allofwhich'are secured togetherfby a plurality of through-bolts '6 locatedin circularly arranged: fashion, atconvenient intervals: around 1 theperipherylofgthej casingj A valve casing se'ction '7 is secured to theintakeiportion 2 by a plurality or; screws j 8, and an outlet casingsection 9 is secured to the compression head portions by apluralityofsscrewsltl.

- Formed withinthetassernbled sections ofytheipump body 1 are'twoparallel bcres'll and 12,within,eachof which are housed like pairsotdiaphragm pistons, di-

moved' to a position to'the left or to the right of the verticaldependent upon the direction of inclination of the rocker arm 24. Theouter end of the toggle lever 31 carries a contact knobor roller 37 forshifting either one of apair of double seatingvalves38 and 39 to aninner seated position defined hereinafter.

The valve '38 is adapted to seattin either an inner (right-hand)position on a seat 40 or an outer (left-hand) position ona seat41dependent uponthe positioning of the toggle lever 31-and contact knob37; With the toggle lever 31 in its right-hand position (as shown)thecontact knob 37 thereof engages a contact head 42 connected to thevalve 38 by' a stem 43 thereby compressing a valve spring 44 andseating-the valve 38 on the valve seat 40.

With the toggle lever 31in its left-hand position and the contact knob37 thereof out of engagementwith the contact head 42, the spring 44biases the valve 38 to its outer (left-hand) position on the'valv'e seat41',

When the valve 38 is seated on seat 40, communication is establishedbetween the pistonchamber 19 and a return pressure sump (not shown) byway of a passage 45, a passage 46, a valve-chamber 47, a passage sur- Iroundingthe stem 43, a'return chamber 49 and a 56connected'to saidreturn sump (not shown) When the valve 38jis seated on seat 41, the'justde scribed communication between chamber 19 and a return sump is closedoff and communication'established be- :tween an intake pipe'Slandlpiston chambers 19 a'nd 22 by way' pf passage 52,-va1ve chamber 47,passage 46 and passage 45 to piston chamber,19 and; passage 53 past anon-return check valve'54 to the piston chamber 22.

' The valve 39 is identical to valve 38, having valve seats '55 and 56,a contact head 57 connected to the valve 39 by a stem 58 and a spring59.

When the contact. knob 37 of the toggle lever 31 engages the contacthead 57 to compress the spring '59 and seat valve 39 on seat 55,communication is established between piston chamber 20 and theaforementioned return sump by way of a passage 60, a passage 61, a valvechamber 62, a passage 63 surrounding stem 58, return chamber 49 and port50 connected to the return sump (not shown).

When the contact knob 37 of the toggle lever 31 is out of engagementwith the contact head 57 of valve 39, the spring 59 will bias the valve39 to seat on seat 56. With the valve 39 seated on seat 56, the justdescribed communication between piston chamber21 is closed oi? and acommunication is established between the intake pipe 51 and pistonchambers 20 and 21 by Way of passage 64, valve chamber 62, passage 61and passage 60 to piston chamber 20 and a passage 65 past a non-returncheck valve-66 to piston chamber 21.

Check valve 54 is positioned in the passage 53 to prevent backflow offluid under pressure from piston chamber 22 to passage 53. A spring 67maintains check valve 54 seated when there is no flow of fluid underpressure from passage 53 to piston chamber 22.

Check valve 66 is positioned in the passage 65 to prevent backflow offluid under pressure from pistonehamber 21 to passage 65. A spring 68maintains check valve 66 seated when there is no flow of fluid underpressure from passage 65 to piston chamber 21.

A check valve 69 is positioned in a passage 70 between piston chamber 21and dampening chambers 71 and 72 connected to an outlet pipe 73 therebypreventing backflow of fluid under pressure from the outlet pipe 73tween piston chamber 22 and dampening chambers 71 and 72 connected tooutlet pipe 73 thereby preventing backflow of fluid under pressure fromthe outlet pipe 73 and dampening chambers 71 and 72 to the piston chamber 22. A spring 77 maintains the check valve 75 seated when there is noflow of fluid under pressure from the, piston chamber 22 to the outletpipe 73.

The outlet pipe 73 leading from dampening chamber 72 is utilized toestablish communication from the pump to a reservoir or other device(not shown). requiring fluid under high pressure.

Operation In operation, fluid under a normal operating pressure (forexample 50 psi.) is supplied to a fluid pressure system in which theillustrated booster pump is connected by the pipe 51. Fluid under 50psi. pressure (hereinafter called the normal pressure) flows from pipe 151 to the passage 64 andthencetassuming toggle lever 31 to be positionedin the right-hand side of vertical) to 1 the valve chamber 62 past'thevalve seat 55 of valve 39 which is seated on valve seat56 by spring 59.The fluid at normal pressure flows from the valve chamber 62 to passage61 and thence to piston chamber 21 via passage 65 past the check valve66, and also to passage 60 and thence to piston chamber 20.

With fluid at normal pressure in both piston chambers 20 and 21 as justdescribed, the diaphragm pistons 13 and 14 will be moved downward andthe pistons 15 and 16 will be moved upward pumping any fluid in thepiston chamber 22 out past the check valve 75 to the outlet pipe 73 andforcing any fluid in the piston chamber 19 to the return sump (notshown) via passages 45 and 46, valve chamber. 47, past the valve seat 41to passage 48..and xetunichamber 49-.and. thence to-the 1101150.

this just described part of the cycle of pumping takes place, the rockerarm 24 is rocked to a position in which the toggle lever 31 will bemoved by spring 33 to a position on the opposite side of arm 30 fromthat shown in the drawing, that is, with the contact knob 37 in aleft-hand position engaging the contact head 57 of valve 39, therebycausing the valve-39 to unseat from the valve seat 56, and seat on thevalve seat 55. Simultaneously with the seating of valve 37 on seat 55,the spring 44 causes the valve 38 to unseat from the valve seat and toseat on valve seat 41.

With valve 39 seated on valve seat 55 and valve 38 unseated from valveseat 40, fluid at normal pressure from the pipe 51 flows to the valvechamber 47 via the passage 52 and past thevalve seat 40. The fluid atnormal pressure flows from the valve chamber 47 via passages 46 and topiston chamber 19, and via passage 53 past the check valve 54 to thepiston chamber 22. Fluid at normal pressure in piston chamber 20remaining from the first part of the cycle of pumping is vented to thereturn sump (not shown) via passages 60 and 61, valve chamber 62, pastthe valve seat 56 and stem 58 to the return chamber 49and thence to thereturn sump via port 50.

From theabove description, it can thus be seen that with piston chambers19, 21 and 22 supplied with fluid at normal pressure and piston chamber20 vented to the return sump, a second part of the cycle of pumping isinitiated. In. the second part of the cycle of pumping, the diaphragmpistons 15 and-16 will be moved downward by a force in opposition to theforce of the pressure in piston chamber 21 of the diaphragm piston 13,said forces being transmitted via the rocker arm 24. Simultaneously withthe downward movement of diaphragm pistons 15 and 16, the normalpressure in piston chamber l 19 is tending to move the diaphragm pistons14 and 13 upwardly against the pressure in piston chamber 21, the

, ing a force on the respective diaphragm pistons 13' and 15,

will also flow to the chambers 71-and 72 past the check ..valves 69 and75 until the pressure of fluid in said chambers builds up to equal thesupply pressure, at which time normal pumping with a boosterefiectbegins as hereinafter described.

With the justdescribedmovement of the diaphragm pistons 15 and 16downward and pistons 13 and 14 upward, the rocker arm- 24 is rocked to aposition in which the spring-33 will pivot the toggle arm 31 about thepin 32 with a snapping action such that the contact knob .37 moves tothe right-hand position out of engagement with contact head 57 andengaging the contact head 42. With the contact knob 37 in its right-handposition, the valve 38 is seated on the valve seat 40 and unseated fromvalve seat 41. The spring 59 of the valve 39 will etfect -movement ofthe valve. 39 to seat on the valve seat 56 and unseat from the valveseat 55.

With the contact knob 37 in its right-hand position,

. and the valves 38 and 39 positioned as described in the previousparagraph, the pump is conditioned again for the first part of the cycleof pumping previously described in which piston chamber 19 is vented toatmosphere and the sum of the normal (S0'p.s.i.) pressure in the twopiston chambers'20 and 21 opposes the normal pressure in chamber 22 topump the fluid in chamber 22 under pressure via passage 70 past thecheck valve 69 to the outlet-pipe73 to .a-"reservoir not shown. Incompleting this first part of the cycle of pumping, the rocker arm '24 rand toggle arm 31 is repositioned to set the inlet valves 38 ,and' 39incondition for repeating the previouslydescribed second part of .thecycle of pumping.

It can thusibe-seen that completion of the first part of the pumpingcycle conditions the pump for initiation of the second part ofthepumping cycle, the completion of which conditions the pump forrepetition of the pumping cycle etc., until the pressure in the chambers71' and v 72 and the reservoir (not shown) connected by outlet pipe 73is equivalent to the total pressure applied by either of the twosimultaneously eifective pistons 14 and 6 1, in which each of saidpiston units comprises'a pair of coaxially spaced pistons connectedtogether by a connecting rod and having an atmospheric pressure chambertherebetween, the axes of movement of said pairs of coaxially spacedpistons being in substantially parallel relation, and in which theopposite extremities of said rocker arm are pivotally connected to saidconnecting effective pistons is twice the inlet pressure and thus thepump will operate theoretically at least to deliver fluid under pressureat double the pressure of fluid from the inlet. It will be apparent thatvariations maybe made without invention in theresp'ective areas of thepairs of diaphragm pistons to provide various corresponding ratios ofthe delivered pressure to the normal pressure other than the theoreticaltwo-to-one ratio effected by the specific structure described.

Having now described the invention, what I claim as new and desire tosecure by Letters Patent is:

1; A fluid pressure booster pump for delivering fluid at a pressurehigher than and in predetermined ratio to that of the fluid suppliedthereto, said pump comprising a casing having a fluid pressure supplyinlet passage and a fluid pressure outlet passage, two piston unitscontained in said casing, each piston unit having a first chamber at oneside and a second chamber on the opposing side thereof, a rocker armpivotally mounted at its mid-point on said casing and connected atopposite extremities thereof to the said piston units respectively so asto transmit a force from one piston unit to the other as said pistonunits oscillate in opposite directions simultaneously, a pair of valvemeans each having afirst position and a second position, levermeansconnected to said rocker arm and operable responsively to movement ofsaid rocker arm approaching one extremity in one direction to operateone of said pair of valve means selectively to its first posirodsrespectively.

5. A pressure booster pump according to claim 1, in which each of saidpiston units comprises a pair of diaphragm pistons fixed in said casingin parallel coaxially spaced relation and having a common piston rodconnecting them together, and in which the extremities of said rockerarm are pivotally connected respectively to the said common piston rodof each piston unit between the diaphragm pistons.

6. A fluid pressure booster pump for delivering fluid at a pressurehigher than and in predetermined ratio to that of the fluid suppliedthereto, said pump comprising a casing having a fluid pressure supplyinlet passage and a fluid pressure outlet passage, two piston unitscontained in said casing, each piston unit having a first chamber at oneside and a second chamber on the opposing side thereof, a rocker armpivotally mounted at its mid-point on said casing and connected atopposite extremities thereof to the said piston units respmtively so asto transmit a force from one piston unit to the other as said pistonunits oscillate in opposite directions simultaneously, a pair of valvemeans each having a first position and a second position, lever meansconnected to said rocker arm and operable responsively to movement ofsaid rocker arm approaching one extremity in one direction to operatetion and the other of said pair-of valve means to its oscillatorymovement of said piston units in opposite directions simultaneously,said first chamber of each piston unit being adapted to act as a fluidpressure compression chamber in which fluid contained therein iscompressed to a degree according to the sum of supply fluid one of saidpair of valve means selectively to its first position and the other ofsaid pair of valve means to its second position, and operableresponsively to movement said first position to so control the supply offluid under pressure from said inlet passage to said first chamber ofone of said piston units and said second chamber of the other of saidpiston units cooperatively with said other of said pair of valve meansbeing operable in its said second position to so control the venting ofsaid second chamber of said one of saidpiston units as to effectmovement of said piston units and said rocker arm towards said oneextremity in said one direction, and said one of said pair of valvemeans being operable in its said second position to so control theventing of said second chamber of said other of said piston unitscooperatively with said other of said pair of valve means being operablein its said one position to so control the supply of fluid underpressure from said inlet passage to said second chamber of said one ofthe piston units and said first chamber of Y the said other of thepiston units as to effect movement pressure forces from said inletpassage acting on both the said connected piston units to 'eflectdelivery to said fluid pressure, outlet passage of fluid at a pressurehaving' corresponding ratio to the pressure of fluid supplied to thepump via said inlet passage.

2. A fluid pressure boster pump as claimed in a claim 1, in which anon-return valve is provided for each of said first chambers to preventback-flow of'fiuid under pressure therefrom. v

3. A fluid pressure booster pump, as claimed in claim 1, having apressure deliverychamber out of which said 7 outlet passage opens, apressure delivery passagev estab- .lishing communication between each ofsaid compression chambers and said pressure delivery chamber, and nonofsaid piston units and said rocker arm'toward said other extremity in theopposite direction, said first chamber of each piston unit acting as afluid pressurecompression chamber in which fluid contained therein iscompressed to a degree according to the sum of supply fluid pressureforces from said inlet passage acting on both the said 6, in which arecheck valvemeans for. preventing back-- flow of fluid pressure from saidcompression chambers.

8. A fluid pressure booster pump for delivering. fluid at a pressurehavinga predetermined higher. pressure than the pressure offluid'supplied thereto, said pump comprising a casing, a first pistonunit and a second piston unit contained in said casing, each piston unithaving a first chamber at one side and a'second chamber on the oppositeside thereof, rocker arm means pivotally mounted at its mid-point tosaid casing and connecting said piston 'units so as to transmit forcefrom one piston unit to the other as they move simultaneously inopposite directions, valve means, a plurality of passage means, saidvalve means operable to one position in which supply of fluid underpressure is eifected to said first chamber of said first piston unit viaone of said passage means and to said second chamber of said secondpiston unit simultaneously via a second passage means, and operative toa second position in which the supply of fluid under pressure iseffected to the said second chamber of said first piston unit via athird passage means and to the said first chamber of said second pistonunit simultaneously via a fourth passage means to cause fluid pressureforces to act thereon simultaneously in opposite directions, toggle armmeans pivotally connected to and operatively controlled by movement ofsaid rocker arm means incidental to movement of said piston units toeflect operation of said valve means to alternately control supply offluid under pressure to said piston units via said plurality of passage,means in a manner to cause reversal'of the fluid pressure forces actingthereon thereby to produce oscillatory movement of said piston unitssimultaneously in opposite direc- 1 tions, said first chamber of eachpiston unit acting-as a fluid pressure compression chamber means inwhich fluid supplied thereto via said plurality of passage means underReferences Cited in the file of this patent UNITED STATES PATENTS491,116 Keeney Feb. 7, 1893 2,550,678 Deacon May 1, 1951 FOREIGN PATENTS325,990 Italy Apr. 22, 1935 840,648 Germany. June 3, 1952

